Wearable technology is a relatively new market that has shown immense potential and has already impacted several business sectors, including health, communication, fashion, energy, and textiles. A variety of wearable devices are now being available. For example, wearable devices may use some form of textile. Smart apparel, for example, is an integration between textiles and wearable technology. Smart apparels may aim to monitor, for example, one or more parameters of the body such as body temperature, and are an area where the need to provide a light weight, thin, and flexible power source is important.